HTML is Dead, Long Live JML

Author: Christos Drogkidis Date: 02-12-2025

Introduction

HTML was the language that built the Web. But today it has become a burden: full of legacy baggage, ambiguities, inconsistencies, and security gaps. Every browser has its own rendering engine, every framework tries to patch the problems, and developers spend countless hours debugging issues that should not exist.

It’s time to say it clearly: HTML is dead.
The future of Web markup is JML (JSON Markup Language).

Why HTML Can’t Continue

Legacy baggage: Decades of backward compatibility
Ambiguity: Tags with unclear or context-dependent behavior
Security: Inline scripts, injection, parsing quirks
Inconsistency: Different results across browsers

What is JML

JML is a new markup language that:

Uses JSON-like syntax syntax for clarity and predictability
Transforms into DSL and AST for safe parsing
Produces HTML only when the structure is fully valid
Provides warnings for structural issues
Supports HTML5, SVG, MathML, custom elements, ARIA, and more — without hacks

JML Example

Traditional HTML

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Profile</title>
    <meta name="description" content="Basic profile page">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="preload" as="style" href="./assets/css/style.css">
    <link rel="icon" type="image/x-icon" href="./favicon.ico">
    <link rel="canonical" href="./">
    <script type="text/javascript" src="./assets/js/app.js"></script>
    <style>
      .card { border: 1px solid #ccc; padding: 16px; border-radius: 8px; }
      .name { font-weight: 600; }
    </style>
  </head>
  <body>
    <header id="top" class="site-header">
      <h1>Welcome</h1>
    </header>
    <main>
      <section class="card">
        <h2 class="name">Jane Doe</h2>
        <p data-info="safe">Front-end developer</p>
        <a href="./contact.html" rel="noopener">Contact</a>
        <img src="./assets/img/avatar.png" alt="Profile photo" width="120" height="120">
      </section>
    </main>
  </body>
</html>

The same page in JML

html:lang('en') {
  head {
    meta:charset('utf-8')
    title {`Profile`}
    meta:name('description'),content('Basic profile page')
    meta:name('viewport'),content('width=device-width, initial-scale=1')
    link:rel('preload'),as('style'),href('./assets/css/style.css')
    link:rel('icon'),type('image/x-icon'),href('./favicon.ico')
    link:rel('canonical'),href('./')
    script:type('text/javascript'),src('./assets/js/app.js')
    style {
      `.card { border: 1px solid #ccc; padding: 16px; border-radius: 8px; }
      .name { font-weight: 600; }`
    }
  }
  body {
    header:id('top'),class('site-header') {
      h1 {`Welcome`}
    }
    main {
      section:class('card') {
        h2:class('name') {`Jane Doe`}
        p:data-info('safe') {`Front-end developer`}
        a:href('./contact.html'),rel('noopener') {`Contact`}
        img:src('./assets/img/avatar.png'),alt('Profile photo'),width('120'),height('120')
      }
    }
  }
}

Internal DSL representation

TAG html LANG 'en'
  TAG head
    TAG meta CHARSET 'utf-8'
    TAG title
      TEXT 'Profile'
    TAG meta NAME 'description' CONTENT 'Basic profile page'
    TAG meta NAME 'viewport' CONTENT 'width=device-width, initial-scale=1'
    TAG link REL 'preload' AS 'style' HREF './assets/css/style.css'
    TAG link REL 'icon' TYPE 'image/x-icon' HREF './favicon.ico'
    TAG link REL 'canonical' HREF './'
    TAG script TYPE 'text/javascript' SRC './assets/js/app.js'
    TAG style
      TEXT '.card { border: 1px solid #ccc; padding: 16px; border-radius: 8px; }
      .name { font-weight: 600; }'
  TAG body
    TAG header ID 'top' CLASS 'site-header'
      TAG h1
        TEXT 'Welcome'
    TAG main
      TAG section CLASS 'card'
        TAG h2 CLASS 'name'
          TEXT 'Jane Doe'
        TAG p DATA-INFO 'safe'
          TEXT 'Front-end developer'
        TAG a HREF './contact.html' REL 'noopener'
          TEXT 'Contact'
        TAG img SRC './assets/img/avatar.png' ALT 'Profile photo' WIDTH '120' HEIGHT '120'

Why JML is Safe

The TJMLValidator class in Ascoos OS stops transformation on any syntax error
Predictable parsing — no “undefined behavior”
Visual warnings for structural issues
Independence from browser DOM quirks

JML Studio – Your online JML editor

JML Studio is the online tool for producing JML documents — just like Microsoft Word is the editor for .docx files, JML Studio is the editor for .jml files.

It offers:

Tabs: Editor · HTML · DSL · AST · HTML to JML
Export to .jml and .html
Online preview: JML to HTML conversion in real time

The Vision

JML is not just another language.
It is the next markup standard:
Clean. Secure. Extensible. Predictable.

With JML, developers won’t waste time debugging quirks. They’ll build on a language that doesn’t betray them.

Conclusion

HTML is dead. Long live JML.

With JML Studio you can start creating and testing JML documents today. But the real power lies in the language itself — the new secure markup for the Web.

Written by Christos Drogkidis — creator of Ascoos OS and the JML language.